Video: Jayson Tatum Explains Celtics' Struggles in NBA Finals Game 4 Loss vs. Mavs

Jayson Tatum and the Boston Celtics faced a historic loss in Game 4 of the NBA Finals, losing to the Dallas Mavericks 122-84.

The 38-point loss was the largest deficit for the Celtics in Finals history, and Tatum believes the blowout can be attributed to Boston's defense.

"I think it starts on the defensive end for us. We didn't get many stops," Tatum said. "So they were allowed to set their defense up, and just naturally, when you're scoring at a high rate, you feel good about yourself."

Game 4 was the first game of the series in which the Celtics allowed more than 100 points, speaking to Tatum's point that the defense was lacking. The sluggish defense made things easy for the Mavs, who already have a high-powered offense.

Tatum also spoke to the Celtics' stagnant performance in the loss.

"I think this is the most stagnant that we've been this series and the worst job of owning our space on the offensive end and doing what we wanted to do instead of what they were forcing us to do," Tatum said. "We did a great job of that in the first three games, and this one we didn't."

The Celtics still have a very comfortable lead in the series, but as Tatum said, they can't be as stagnant as they were in Game 4 if they want to avoid blowing a 3-0 lead.

But Boston can't dwell on the blowout loss for long as it prepares for Game 5.

"You have to move on from it, win or loss," Tatum said. "We're obviously going to watch film and see a lot of things we need to clean up and do better. But you can't worry about it too much because we have another game on Monday... We've got to be a lot better, and I believe that we will."

The series will return to Boston for Game 5, where the Celtics can clinch the series and win their 18th title in franchise history.